Superbomb: history and myths

On 12 August 1953 the USSR detonated the first “practical” thermonuclear bomb. The correspondent of the “Attic” tells the story of its inception and understands, is it true that such ammunition almost does not pollute the environment, but can destroy the world.

The idea of thermonuclear weapons, where the nuclei of atoms merge, not split, as in the atomic bomb, appeared before 1941. She came into the heads of physicists Enrico Fermi and Edward Teller. Around the same time they became members of the Manhattan project and helped create the bombs dropped on Hiroshima and Nagasaki. To construct a thermonuclear warhead was much more difficult.

Some understanding of how a thermonuclear bomb atomic is harder, and the fact that operating nuclear power plants a long time routine, and working and practical fusion power is still science fiction.

To atomic nuclei merge with each other, they must be heated to millions of degrees. The scheme of the device that would allow this to be done, the Americans patented in 1946 (project informally known as the Super), but remembered about it only three years later, when the Soviet Union successfully tested a nuclear bomb.

U.S. President Harry Truman announced that the Soviet breakthrough you need to answer the “so-called hydrogen or superbomb”.

By 1951, Americans have created a device and tested under the code name “George”. The design was a Thor — simply put, the bagel with heavy isotopes of hydrogen, deuterium and tritium: chose them because such nuclei merge is simpler than the nucleus of ordinary hydrogen. The heat was provided by nuclear bomb. The explosion of a compressed deuterium and tritium, those merged, given the fast neutron flux and lit the surface with uranium. In a conventional atomic bomb he does not share: there is only slow neutrons, which cannot be forced to share a stable isotope of uranium. Although the energy of nuclear fusion had approximately 10% of the total energy of the explosion, “George”, “ignition” of uranium-238 is allowed to raise the power of the explosion twice the normal size to 225 kilotons.

Due to the additional uranium explosion happened twice more powerful than ordinary atomic bomb. But fusion had only 10% of the released energy: the tests showed that hydrogen nuclei are compressed hard enough.

Then the mathematician Stanislaw Ulam suggested a different approach: a two-stage nuclear fuse. His idea was to put in the “h” zone of the device plutonium rod. The explosion of the first fuse “burned” plutonium, two shock waves and two streams of x-rays faced the pressure and the temperature jumped enough to start nuclear fusion. A new device tested on enewetak Atoll in the Pacific ocean in 1952 — the explosive power of the bomb amounted to ten megatons of TNT.

To the hydrogen nucleus are merged, the distance between them should be minimal, so the deuterium and tritium cooled to a liquid state near absolute zero. This required a huge cryogenic installation. Second thermonuclear device — in fact, enhanced modification “George” — weighed 70 tons: the plane is not reset.

The Soviet approach

The Soviet Union began to develop a thermonuclear bomb, later the first scheme was proposed by Soviet developers only in 1949. It was supposed to use lithium deuteride. It’s metal, solid, it is not necessary to liquefy, and therefore a bulky refrigerator, as in the American version, is no longer required. Not less important is the fact that lithium-6 in the bombardment of neutrons from the explosion gave helium and tritium, which further simplifies the fusion of the nuclei.